Title:
種々の記録媒体用のコピー防止の方法及び装置
Document Type and Number:
Japanese Patent JP4023818
Kind Code:
B2
Abstract:
A method and apparatus for copyright protection for various recording media such as compact discs (CDs) uses a combination of symmetrical and asymmetrical data encryption to permit the player to handle either copy-protected or non-copy-protected media, in a manner that is extremely difficult to compromise. Coupled with the combination of encrypting methods, an Authenticating Signature is recorded on the media only when copy-protection is required. The nature of this Authenticating Signature is such that it will not be transferred to illicit copies made on CD recorders. When either an original protected or an original non-protected disk is played, the presence or absence of the Authenticating Signature causes the player to correctly decrypt the program data. All original CDs therefore play normally. When a copy of a non-protected CD is played, the absence of the Authenticating Signature also causes the player to correctly decrypt the program data. However, when a copy of a protected CD is played, the absence of the Authenticating Signature causes the player to generate false data which prohibits the disk from playing normally.
Inventors:
Ryan, John Oh
Application Number:
JP50346896A
Publication Date:
December 19, 2007
Filing Date:
June 27, 1995
Export Citation:
Assignee:
Macrovision Corporation
International Classes:
G11B20/10; G09C1/00; G11B20/00; H04L9/14; H04L9/32; H04N5/913; G06F1/00; G06F7/72
Domestic Patent References:
| JP5257816A | ||||
| JP2293930A | ||||
| JP63132336A | ||||
| JP1182971A | ||||
| JP697931A | ||||
| JP669915A | ||||
| JP3102592A | ||||
| JP340689A |
Attorney, Agent or Firm:
Tadahiko Ito